Compared to an artery, the wall of a vein differs in which of the following ways: A)it contains smooth muscle B)it consists of three layers C)the middle layer is thin D)the outer layer is composed largely of collagen fibers E)it is lined by a thin layer of endothelium

A decrease in venous return to the heart causes: A)a decrease in stroke volume and a decrease in cardiac output B)a decrease in stroke volume and an increase in cardiac output C)an increase in stroke volume and an increase in cardiac output D)an increase in stroke volume and a decrease in cardiac output E)no change in stroke volume and no change in cardiac output

The carotid artery is located in the: A)axilla B)groin C)neck D)abdomen E)leg

The umbilical vein carries: A)metabolic wastes and carbon dioxide from the fetus to the placenta B)metabolic wastes and carbon dioxide from the placenta to the fetus C)oxygen and foods from the fetus to the placenta D)oxygen and foods from the placenta to the fetus E)blood from the navel into the inferior vena cava

Vasoconstriction occurs as a result of: A)an increase in parasympathetic nervous system firing B)a decrease in parasympathetic nervous system firing C)an increase in sympathetic nervous system firing D)a decrease in sympathetic nervous system firing E)an increase in blood pressure

Which of the following is the function of renin and aldosterone: A)they are produced whenever blood pressure rises and ultimately cause an increase in blood volume and blood pressure B)they are produced whenever blood pressure rises and ultimately cause a decrease in blood volume and blood pressure C)they are produced when blood pressure rises and have no long-term effect on blood volume and blood pressure D)they are produced whenever blood pressure falls and ultimately cause an increase in blood volume and blood pressure E)they are produced whenever blood pressure falls and ultimately cause a decrease in blood volume and blood pressure

Substances tend to leave the bloodstream at the arterial end of the capillary because: A)the osmotic pressure of the blood is higher at the arterial end of the capillary B)the osmotic pressure of the blood is higher at the venous end of the capillary C)blood pressure is higher at the arterial end of the capillary D)blood pressure is higher at the venous end of the capillary E)interstitial pressure is higher at the arterial end of the capillary